The present invention relates specifically to the field of medical and dental assistant's chairs and stools and generally to chairs and stools having body support members. Most common chairs and stools have, at a minimum, a surface that is generally parallel to the ground upon which a person or occupant sits. This surface is sometimes referred to as the seat of the stool or chair. In addition there may be an additional structure often referred to as a backrest. The backrest is generally substantially perpendicular to the seat. The function of the backrest is to provide a surface for the occupant of the stool or chair to rest his or her back against. This surface also provides back support for the occupant.
Specialized seating, including chairs and stools, is often used in the medical and dental profession. Because it is often necessary for the medical personnel to perform one or more procedures on a patient, seating for medical persons must be specially designed taking into account such things as the comfort of the medical provider, the comfort of the patient, and the safety of both the provider and patient.
It is often necessary that the medical provider lean over or position oneself directly over the patient in order to perform a medical treatment. A chair or stool having a traditional backrest, as described above, would be of little benefit in this situation. Instead requiring a structure that provides support to the back of the medical provider, a device that provides support to the front or abdomen of the person is necessary. This is achieved with the use of a chair or stool having a body support member. The body support member usually replaces the traditional backrest.
A body support is an elongated padded member that may be curved along its longitudinal axis. It is typically supported at one end by an arm or bracket that extends from the underside of the chair or stool seat to the body support. The height and position of the body support should be adjustable so that optimum comfort is imparted upon the chair or stool occupant.
A chair or stool having a body support member is designed for an application where the occupant must lean forward a predetermined amount and still requires support so as to not fall out of the chair or stool. This may occur when a patient is situated in a dental chair and the medical personnel must lean over the patient to administer medical treatment in the patient's mouth. Alternatively, the patient may be located in a bed and the medical personnel again must lean over the patient to initiate and complete a medical procedure. As opposed to a back support, the body support contacts the chair or stool occupant at the abdomen and thus provides support while restraining the occupant from leaning too far forward. Besides aiding in the comfort of the medical personnel, a body support also provides a degree of safety by restraining the medical personnel and preventing a situation in which the care giver may lean too far forward, lose his or her balance and thus fall onto the patient. The restraint provided by the body support adds to the comfort of the patient as well by creating a visible barrier upon which the medical provider can rely for support and balance.
In prior art chair and stool designs incorporating body supports, it was difficult to easily adjust the position of the body support relative to the position of the chair or stool seat. Prior art chair and stools having body support members require the occupant to either permanently lock the body support into place or to operate cumbersome mechanisms in order to easily adjust the body support. In the first case, permanency of the relative position of the body support with respect to the seat makes ingress and egress of the chair or stool difficult. A person must maneuver or work around the obstacle of the permanently positioned body support in order to sit down on or stand up from the chair or stool. In the latter situation, if it is too difficult to adjust the body support, the person is likely to not use the support or to rely upon the support when it is not locked into position. Either case provides a safety hazard to the occupant and patient.
The present invention comprises a novel construction of a body support ratcheting mechanism. The invention is placed between the body support structure and the bracket that extends from the underside of the chair or stool. The mechanism allows the body support to easily pivot about its support bracket and relative to the seat.
My invention provides a body support mechanism that is easy to operate, positively locks the body support into a locked position, unlocks for easy ingress to and egress from the chair or stool, and allows for adjustment during use. These and other benefits of my invention will become evident in the descriptions that follow.